1. Field of the Invention
This invention relates generally to the field of video distribution networks. In particular, this invention relates to secure video distribution networks.
2. Description of the Background Art
Security is an important issue for video distribution networks. For cable distribution networks, there are various portions or locations where security is of concern.
A first portion where security is of concern is the primary distribution network. The primary distribution network is where video content is transferred from television studios to distribution centers. A second portion where security is of concern is the secondary distribution network. The secondary distribution network is where the video content is transmitted from a distribution center to subscriber stations.
For video on-demand distribution networks, there is an additional point where security is of concern. That point is a remote server within a distribution center. Typically, such a remote server stores the video content before the video content is distributed to the subscriber stations.
The present invention provides a solution to the security issues presented above, especially with regards to security at a remote server. In accordance with a first aspect of the invention, a remote server receives video programming in a first encrypted form and stores the video programming in the first encrypted form. After the remote server receives a request from a subscriber station for transmission of the video programming, the remote server decrypts the video programming, re-encrypts the video programming into a second encrypted form, and then transmits the video programming in the second encrypted form to the subscriber station.
In accordance with a second aspect of the invention, a remote server receives video programming in a first encrypted form, decrypts the video programming, re-encrypts the video programming into a second encrypted form, and then stores the video programming in the second encrypted form. After the remote server receives a request from a subscriber station for transmission of the video programming, the remote server simply transmits the video programming in the second encrypted form to the subscriber station.
In accordance with a third aspect of the invention, a remote server receives video programming in a first encrypted form and stores the video programming in the first encrypted form. After the remote server receives a request from a subscriber station for transmission of the video programming, the remote server passes through the video content by transmitting the video programming in the first encrypted form to the subscriber station.
In accordance with a fourth aspect of the invention, a remote server receives pre-encrypted video programming and stores the pre-encrypted video programming. After the remote server receives a request from a subscriber station for transmission of the video programming, the remote server completes encryption of the video programming and then transmits the video programming to the subscriber station. At the subscriber station, the video programming is fully decrypted.